Ruy Lopez d5 instead of d6

Why is it in this position black plays 8.d6 instead of 8.d5? It seems like d5 would be a more aggressive/active move.

you must know either side of the marshall. if you dont know theory, and your opponent does, you may already be in serious trouble of losing within 6 or 7 moves.

False. The Marshall Attack is far from a draw offer.

Most GM's avoid it because they fear it.

Why in the world are there a couple of class c players debating the value of the Marshal versus the Closed Spanish on the internet? Ohh well, I might as well weigh in; I have a theory that grandmasters avoid positions that computers play and analysis correctly in order to avoid preparation. The Marshal is an opening that the computers analyze correctly, the Berlin is not. Top level players are more likely to play the Berlin then the Marshal because there "positional understanding" actual counts for something in the Marshal. Other lines that grandmasters avoid include the mainline Zaitsev, they seem to prefer 12. d5, which is quickly fading as an actual winning attempt. Even the open Sicilian has become rare at the top. What are we left with? Berlins and an early d3 in the Ruy, the Rosolimo and the Catalan.

My two cents, more on topic 7..d6 is more accurate for entering the Closed Spanish, but the a4 lines are not considered dangerous at the moment.

Please find evidence that computers have a hard time analyzing the Berlin. It's quite the opposite for Rybka.

Well you first, which grandmaster fears the Marshal Attack. Also I very much doubt you got my point.

Any grandmaster that plays the 8.h3 move order IMO fears the Marshall.

Kasparov would be a good example, since he plays anti-Marshall lines very often.

Here is a nice game:

Ok, so this is a good move. Thx guys.

How do you know he was not avoiding an over analyzed line that would result in a draw with very little scope for creative play?

IMO any line you want to consistently avoid, you "fear"

I don't think Kasparov would mind a draw. Anyways, the line hasn't been analyzed to a draw. Kasparov avoids it because it's complicated, and because a well-prepared opponent can catch him by surprise.

Didn't Nigel Short deafeat him with the line, or was that someone else?

Not really, I don't want to face 1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. d4 exd4 5. O-O Nxe4 6. Re1 d5 7. Bxd5 Qxd5 8. Nc3 Qh5 9. Nxe5 Be6 10. Bg5 Bd6 11. Nxd6 dxd6 12. Bf4 Qd5 from a lower rated opponent who only wants to draw that does not mean I "fear" the line. Also is that the Kramnik Leko game that Kramnik followed his computer untill he had a losing position? I should mention that it was not until the Kramnik-Topolov match that I begin to get the sense that the top players were avoiding purely computer preperation.

You are more likely to lose than to draw against a lower-rated opponent who has studied the line. Don't underestimate the opening.

"The Marshall Attack is one of the oldest and most important openings in the history of chess. It is perhaps because of this reason that as white many Grandmasters, including the world number one Gary Kasparov, have decided to avoid the issue altogether, preferring the more tranquil waters of Anti-Marshall systems"

ChessBase

Admit it. You don't understand the line at all. You only know the basics.

You quoted an ad? I'll admit that I am making stuff up as I go along as soon as you do, I screwed up the last diagram It was suppose to read that every position in Chess 365 database that reached that position was drawn and then give a site to the Shirov Aronian game. I also diden't mention the idea of Bh3, Qf1 and Bd1 in the test position.

One the Marshal attack is not very old, Capablanca-Marshal New York 1918 is under 100. Two who wrote that for chessbase? From the context we can conclude it is not Kasporov. Three it is some sort of ad.

Why do we insist that we understand what we do not? Why do you tell me what a retired chess player champion thinks?

Dude your highest rating is 1293 and you insist that you know why grandmasters do anything. I know that finding an anotated version of Capablanca-Marshal 1918 and going over it would be a better use of both of our time. As would you know basic endgame theory.